Reconsidering pterygium in the context of focal limbal stem cell dysfunction

Limbal stem cell deficiency (LSCD) is traditionally regarded as a rare ocular surface disorder characterised by impaired corneal epithelial regeneration. Emerging evidence suggests that pterygium, a common fibrovascular lesion extending onto the cornea, may involve focal limbal epithelial or niche dysfunction. This narrative review examines clinical, histopathological and biological evidence relevant to the relationship between pterygium and focal limbal dysfunction. The peripheral light focusing hypothesis provides a biologically plausible explanation for the characteristic nasal predilection of pterygium through localised ultraviolet-related stress at the limbus, further influenced by environmental and anatomical factors. Histopathological studies have reported altered expression of limbal epithelial-associated markers in pterygium tissue, supporting possible disturbance of limbal barrier function and epithelial homoeostasis. However, these findings remain supportive rather than definitive and should be interpreted alongside established inflammatory, fibrovascular and ultraviolet-related models of pterygium pathogenesis. Pterygium may be usefully reconsidered within the framework of focal limbal dysfunction, particularly in recurrent or biologically aggressive cases. This perspective may broaden current understanding of ocular surface disease and support continued interest in limbal-preserving and regenerative strategies, including carefully defined limbal epithelial reconstruction approaches in selected contexts aimed at reducing recurrence and restoring ocular surface stability. However, current evidence remains insufficient to justify formal reclassification of pterygium as established localised LSCD or to mandate practice-changing therapeutic conclusions.